Inclosed liquid-fuel burner



Nov. 22, 1927. 1,650,342

J. GOOD INCLOSED LIQUID FUEL BURNER Original Filed May 1. 1918 WNVENTOR TTORNEY Patented Nov. 22, 1927.

g UNITED; STATES JOHN GOOD, OF BROOKLYN, NEW YORK,

ASSIGNOR TO GOOD INVENTIONS 00.,

NEW YORK, N. Y., A CORPORATION OF'NEW YORK.

INGLOSED LIQUID-FUEL BURNER.

Application fiIed May 1, 1918, Serial No. 231,910. Renewed September 26, 1925.

The invention relates to the organization of the. elements of burners and especially those which are ignited by an electric spark, the purpose being to enlarge the permissible range of structural and adjustment variations of the various elements. It is directed especially toward maintaining the fuel in liquid form up to the point of delivery into the combustion space, a certain disposition of the igniting spark plug which tends to keep the plug body clean and free of soot and fuel, and a certain special disposition of the spark plug terminals with respect to the mixture which tends toward certainty of ignition under different conditions.

The accompanying drawing illustrates the invention in both of its features combined in an inclosed liquid fuel burner, the figure being a central longitudinal section.

The said burner is not materially different in function from that shown in my co-pendingzapplication Serial No. 195,506 filedOctober 9, 1917. A flow of air from a fan or other air source enters the burner casing 1 from a pipe 2 and part of it passes through a jet hole or nozzle 3 in the end of the shell 4 while the remainder passes into the annular space between shell and easing from which it enters to the interior of the shell through 0 the zone of fine holes 5. The air from the nozzle 3 atomizes liquid fuel from the nozzle 6 connecting with the liquid fuel in a receptacle 7 and thereby pro ects a liquid spray into and through the shell 4. The receptacle 7 is subject to a pressure difference as by the pressure connection 8 to the air pipe 2, which is desirable if the receptacle is far below the nozzle orifice or if a high conjibilggtion rate is desired with low air ressures. The air jet hole 3 may be and pre erably is in aspirating relation to the liquid orifice, but depending on the pressure imparted to the liquid fuel in receptacle 7 this maybe varied as circumstances may dictate. When the burner is intended for continuous operation such a pressure pipe is desirably provided with a sinall adjustable vent-hole 9 to prevent an accumulation of pressure in the receptacle. The atomized liquid spray is ignited, priorto its mixture with the inward flow of combustion-supporting air from the holes 5,

are mounted so as to bring the spark gap at the spray source as and for this reason the electrodes 10 and 11 of the double-electrode spark plug to the spray source and intercepting the spray therefrom. The resulting flame receives more air through the air holes in the flange of the shell and passes from the ignition chamber within the shell into the flame tube or other enclosed space to be heated, escaping from the latter to an outletiopen to atmosphere but not shown. The air flow to the ignition and mixing chamber may be produced by any suitable means independent of the flame establishing a difference of pressure between the outlet to the flame passage and the pipe 2.

The electrodes 10 and 11 are carried respectively by the metallic shell 13 and the insulating core 14 of the spark plug. This latter is screwed into the end of a tubular neck 15 projecting from the shell 4, the electrodes being of such length as to extend through the interior cavity within this neck to the position desired for the spark gap in the interior of the ignition chamber. Except for the length of the electrodes, the plug may be of ordinary, properly insulated construction having an annular cavity 16 within its shell 13 as usual. The cavity represented by the-interior of the neck 15 forms plug cavity and is an extension of the spark located preferably in the upper side of the shell of the ignition chamber and as close to possible without however being directly in line with the-fuel nozzle so that a liquid jet from the latter would enter it and wet the interior of the plug.

The entrance to the neck cavity is also outside of the lateral boundaries of the spray cone from the spraying means indicated by the dotted lines so that the spray cannot directly enter into it, but the spark-gap is nevertheless directly in the path of the iquid spray as above stated. Otherwise'the neck construction of the ignition chamber may be of various shapes and may or may not be integral "with the shell as preferred. The object is to obtain a cavity or dead end pocket of considerable depth surroundin the electrodes of the spark plug. The sai cavity is, by preference, inclined toward the air pipe .2 which position is preferred because it brings the entrance to the cavity substantially parallel to the side of the spray cone and improves and reduces the external contour of the apparatus as a whole, while at the same time permitting a maximum length of cavity. The terminal of the grounded electrode 10 is shown in the draw-,

mg as bent transversel to form the sparkg'ap, this being desirab e in that it tends to dram impinging liquid away and to keep it from bridging the gap and thereby a more moderate sparking current is rendered possible of use but this formation is not essential with an adequatev sparking current and especially when the electrodesare mounted in an inclined cavity as shown in the drawing because the ve considerable force of spray tends to pro uce the same effect by blowing the li uid away from the gap and preventing it rom collecting'thereon. Thefuel nozzle 6 is permanently fastened to the outer shell of casing 1 and between the two shells it is constituted of a relatively slender tube which is directly exposed to and crosses the air passage which leads the combustionsupporting air to the ignition and mixing chamber. It is thereby cooled, the heat conducted to it through its metallic surroundings being dissipated to the air current at a suflicient rate to avoid the ssibilityof vaporization of theliquid within the nozzle.

nasmuch as the capacity of the bore of the fuel nozzle is determined with reference to the air flow, the vaporization of even a part of the liquid in the nozzle and the corresponding change of volume resulting from such vaporization, operates to change the proportions of fuel and air to such extent-as to interrupt combustion or forestall ignition outside of'the spray cone a very high degree of reliability is attained. The part of the are merely for facilitating the dissipation of its heat. Certain features of the structure of the burner above disclosed and not herein claimed form'the subject of my prior application above referred to and certain other applications.

1 claim:

1. In apparatus for burning liquid fuel, an inner shell constituting a fuel-mixing and flame chamber and having an outlet for the flame and combustion products, an outer burner cazin providing a passage for air to said cham er and having an air entrance remote from the heat of the combustion, a liquid fuel supply chamber, a nozzle tube a apted to conduct the liquid fuel therein to said chamber, saidtube being provided with a heat-dissipating rib means exposed to the air flowing in the space between said outer casing and inner chamber and being thereby maintained at a relativel low temperature.

2.. A burner for liquid uel having an igni-' tion and mixing chamber, means for admitting combustion air into said chamber, a

fuel spray nozzle opening into said chamber, and an electric igniter for igniting the mixture within the chamber, said igniter bein set in a cavity which is in the upper portion of the burner and is inclined away from the source of spray and the entrance to which is outside the zone of the spray from said nozzle, the igniting portion of said igniter extending from the cavity to a point within the zone of the spray.

In testimony whereof, I have signed this specification.

' JOHN GOOD. 

